The uses of heating or cooling applicators to the skin for the treatment of injuries and pain have been used for a long time. These techniques are also known to improve the flexibility of tendons and ligaments, reduce muscle spasms and alleviate pain.
Heat therapy (also known as thermotherapy) is the heating of tissue by using various techniques, such as hot water bottles filled with hot water or cloth soaked in hot water, blankets or pads heated by internal electrical heating coils, or the application of ultrasound energy. Heat therapy leads to vasodilation, which in turn increases the blood flow in the affected tissues. The increased blood flow in the target area provides extra oxygen and other nutrients, thus accelerating the healing process. Additionally, the application of heat reduces muscle spasm and relaxes stretched muscles leading to pain relief. Heat or thermotherapy is generally used to treat chronic pain such as low back pain, spinal, neck pain, neuropathic pain, and other muscular spasms. Thermotherapy is generally applied in temperature range of 40-50° C.
Cold therapy (also known as cryotherapy), can be accomplished by using ice or a chemical gel. Cold therapy is typically used during the first one to two days after an injury, typically to get relief from bruises, bumps and sprains. Cold therapy soothes damaged tissues, causes vasoconstriction, which reduces blood circulation and thus numbs the nerves, decreasing inflammation, pain, and muscle spasm. Cold or cryotherapy is generally used to treat acute pain caused due to injuries such as runner's knee and freshly pulled muscle. Cryotherapy is generally applied in temperature range of 5-20° C.
Both therapies are effective for the treatment of edema and pain while being non-addictive and non-invasive.
Contrast therapy is another form of treatment which combines hot and cold therapy. It is performed through the alternate application of hot and cold packs on the skin of an injured area. It decreases pain, increases circulation, and speeds healing. Contrast therapy is used on sports injuries, chronic or repetitive injuries and injuries in the subacute stages of healing
In terms of available products, the hot and cold therapy packs market can be divided into dry and moist hot and cold packs or compresses, gel packs, and electric hot/cold packs. There are many drawbacks to the products currently on the market that compromise their application:
Regarding heating, there are several techniques used to create a hot applicator. For example, some packs are designed to be microwaved, which suffer from drawbacks such as difficulty in controlling the temperature, can become too hot causing burns, and lose heat rapidly, necessitating the need to be reheated. Chemical packs are also commonly used, but they also have limitations based on lack of temperature control; they can leak and are therefore prone to cause chemical burns. The use of an electric heating coil in the pad is commonly used, but often does not have temperature control.
For cooling, ice packs that are kept in the freezer are most commonly used. They do not control temperature—the affected area can become too cold causing possible cold burns, they heat up rapidly, requiring the pack be frequently exchanged with a freshly cooled pack and placed back in the freezer to be refrozen. Chemical ice packs have the same drawbacks as the chemical heating packs. Pumped water from a container containing ice and water for cold therapy are bulky, require ice and water on hand. Further, the water can spill/leak, and there is no true temperature control.
To do combined heating and cooling therapy (contrast therapy) using these standard products would obviously require the purchase of two separate sets of products thus being expensive, requiring extra storage space and consuming a lot of time during application.